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#177857 - 05/13/08 06:47 PM Metal halide light tripping
schenimann Offline
Member

Registered: 02/18/08
Posts: 194
Loc: Western North Carolina
I went on a service call yesterday. In a store downtown, a lady had a 250 watt metal halide light that would trip off then come back on. The breaker never trips, only the light. It would do this once, maybe twice a day, sometimes not at all. It is a fairly new fixture, isn't in a location where it would build up excessive heat and it is a 250w ballast.

The outlet that it is plugged into was originally a 220 outlet converted to a 110. Whoever had worked on it previously had used one of the hots and the ground as a neutral. Our fix was to use the other hot as a neutral and yes, we did go to every jbox we could trace and mark it neutral. Would using the ground as a neutral cause the light to trip? If not, what else?

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#177859 - 05/13/08 07:03 PM Re: Metal halide light tripping [Re: schenimann]
sparkyinak Offline
Member

Registered: 07/08/07
Posts: 1308
Loc: Alaska
Bad bulbs. HPS does the same thing
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#177860 - 05/13/08 07:33 PM Re: Metal halide light tripping [Re: sparkyinak]
twh Offline
Member

Registered: 03/11/04
Posts: 899
Loc: Regina, Sask.
I agree a bad HPS bulb will cycle. I'm not sure about MH bulbs. I thought I saw it last week, but when I suggested a new bulb, the carpenters were all over me. They had already tracked it down to voltage drop when another piece of equipment started. Now, I don't think I've seen an MH bulb do that.

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#177861 - 05/13/08 08:26 PM Re: Metal halide light tripping [Re: twh]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
You probably had a high resistance ground ... this had the effect of lowering the voltage .... not enough volts, bulb would try to re-strike.

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#177862 - 05/13/08 08:28 PM Re: Metal halide light tripping [Re: renosteinke]
schenimann Offline
Member

Registered: 02/18/08
Posts: 194
Loc: Western North Carolina
Should fixing the neutral fix this?

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